Mechanical horn.



G. G. DEAN.

MECHANICAL HORN. APPLICATION PILE? TE'B. 10, 1913. 1,105,324. Pateutei July; 28, ELM

rv n y f l e y /f STFKRONH Ry UNITED srAtrEsPATENr OEEIOE.

-GEORGE C. DEAN, F BRONXVILLE, NEW YORK, ASSIGNOIRI,l E# MESNE ASSIGNMENTS, TQ LOVELL-MCCONNELL MANUFAQTURING COMPANY, .A CORPORATION OF DELA- WARE.'

MEcnANIcAL HORN.l

Specification of Letters Patent.

Original application filed July 10, 1911, Serial-No. 637,678. Divided and this application led February 10,

1913.' serial No. 747,336.

To all whom it may concern:

` Bo it known that I, GEORGE COOPER DEAN, a citizen oi the United States, and resident of' Bronxville, lVestchester county, New York, have invented certain new and useful. Improvements in Mechanical I-Iorns, lof which the following is a specification.

This invention relates to signal or alarm devices, of that type in which there is em-` ployed a diaphragm or' other vibratory sound producing member and means for set ting up vibration of the required frequency and amplitude. In such signals the diaphragm is usually actuated by means of a rotary member, which is driven by .power means, usually in the form of an electric motor. Suitable connections or instrumentalities are employed which arev capable ofv converting the rotary movement of the driver into reciprocatory movement of the diaphragm. The diaphragm being elastic, vibration may be set up and maintained by repeatedly displacing it .in either direction from normal, since such displacement will put it under elastic stress causing it to return to `or past normal position upon cessation of the displacing eiiort. Or the diaphragm may be displaced in both directions. In some cases the driving shaft or rotary member is provided with one or more eccentric portions or projections, constituting a cam or series of cams, the path of which is intercepted by a projection carried by the diaphragm. In other cases a separate thrust connection or a freely vibrated part has been interposed between the cam and the diaphragm.

This application is a division of my prior application, Serial No. 637,678, led .I uly 10th, 1911, and the invention herein claimed resides solely in the construction and arrangement oi.` the parts for driving a rotary i member and in the means for supporting said parts 'and facilitating adjustment in re spect to the diaphragm.

The novel `featuresof construction herein i afterAl described andby means of which the .diaphragm is caused to vibrate upon the rotation of the" rotary member form nopor tionof the present invention and are not claimed herein,`the same being claimed in a co-'pending-application.

` It will be apparent from the following de- Patented July 28,1914.

in placeof the mechanism herein disclosed 4 without necessitating any change in the construction,mounting'and adjustment of the motor which involve the novel features hereinaftervclaimed. j

In the present invention I so mount the motor that it may be bodily rotated about an axis'preferably normal to the diaphragm 1 to secure the proper adjustment ofthe rotor in respect to the diaphragm. By employing a threaded connection between the motor casing or vshell and a portion of the dia-l phragm casing a verydelicate adjustment is secured by a relative rotation of the"parts.

This adjustment of the motor may be uti-l .Y i

lized to vary the operative relationship ofl the rotor to the diaphragm although supplemental adjusting means may also be employed if desired. The motor.casing or shell preferably has spaced end Walls including bearings for the 'armature shaft. One of these walls is preferably substantially parallel to the diaphragm and spaced only a short distance therefrom `so as to form, withl the diaphragm supporting member and the diaphragm, a substantially air tight chamber in the rear 'of the diaphragm and in which the air may be comprcssed'and expanded during the vibration-of the diaphragm. The adjustment ofthe motor toward and from .the diaphragm also serves to adjustA this end wall toward and from the diaphragm and vary the volume of the air chamber in the rear of the diaphragm.

In the accompanying drawings illustrating one embodiment of my invention, Figure 1. is a'y vertical longitudinal section through a warning or signaling device, the

'horn being partly broken away; Fig. 2 is a section On the line 2-2 of Fig; 1, and Fig. 3 is a semi-diagrammatic view, showing the relation between Athe particular cam,

illustrated in Figs. 1 and 2.

In the horn illustrated -I employ a. diaphragm 1, held between clamps 2 and' 3 forming marginal portionsof the two secdiaphragm. balls, and their guide member i .tions 13 and' 1G going to makeup the diaphragm supporting and inclosing casing. The clampingl portions are held together by suitable screws Il, and gaskets of cork or yother suitable material engage With the opposite sides of the diaphragm at the clamped reside in the construction of this motor, and

the method of mountinaf and adjusting the same in respect to the diaphragm. The motor: includes a substantially cylindrical metal ease or motor shell 20 concentric with the axis and having cores for the field coils 25 integral therewith and' projecting inwardly toward the armature 21. The motor 1 casing has an' end wall 22 preferably integral '25 'therewith and disposed substantially parallel tothe diaphragm and so positioned as to be 'normally spaced a short distance from the diaphragm as hereinafter more particularly' Iinted out. This end wall has a bearing 23 orthe armature' shaft 6,-said bearing being disposed between the armature and the rotor ror head 7. At the opposite end of the motor case is a removable end wall or cap 29 which preferably has. an outwardly projecting boss thereon into which one end of the armature shaft projects so as to constitute a. bearing vor the latter and Within this boss 30 may be any suitable thrust bearing 24. For securing the motor in position and facilitating its adjustment, I preferablyy provide the rear casing section 13, which is of annular or rinO form, with a rearwardly extending cylindiical iiange 27. The motor casing is mounted to telescope with the flange 27 and is provided with a part 26 closely iitting within said flange. The part 27 is interiorly threaded and the part 26 is exte riorly threaded, so that the motor is secured in place by a relativo rotationl of the motor casing, and the section or ring 13 .and the.

rotation of the motor in one direction advances it and itsrhead or rotor toward the diaphragm. When the motor has been rotated to a suliicient extent to firmly support it and a sufficient extent to bring the rotor head into proper operative position in respect tothe diaphragm, it may be locked against further rotation 'and held rigidly in 'place by a lock nut 28 threaded on the motor easing part 26 and abutting against the end of the horn casing part 27. lt will be noted that by means of this simple supporting mechanism the motor may be readily and quickly removed from the remainder oi the horn Whenever desired. and when in place may be rigidly heldagainst movement. The proper vpositioning of the motor may be secured with great delicacy due to the comparatively large diameter of the threaded portion and the low pitch of the threads. I may rely upon this adjustment as the only f one for securing the proper positioning of" the rotor, in respect to the diaphra m, or auxiliar 1 adjusting mechanism may e ernployed tor varying the position of the cam with respect to the diaphragm and independently of a movement of the motor case as will be hereinafter particularly pointed out.

For effecting the vibration o" the diaphragrnby .the rotation of the head 7 any suitable means may belein'ployed and the articular means illustrated is not claimed erein, although forming the subjectmatter of a separate'and eopending application. In this specific construction the head 7 is provided with a face'cam 8 encirclinr the same and adjustable in respect to theaody of the rotor and between the face cam and the diaphragm is a series of balls 10 disposed in pockets or guide openings 12 in a g ride member 11 forming a part of or car- Aried'by an inwardly extendin flange portion of the rear casing mem er 13.- The` uide member 11 is stationary andthe nam 8 is rotated by the rotation of the head 7 and 95" shaft G. The cam 8 is illustrated as beingl .i formed separately from the head 7 and secured thereto' by screw threads or'otherwise; and the holder or guide member 1l is illujsj trated as a ring screw or otherwise 'adjustably secured to the stationary :cinal or annu. lar diaphragm ,supporting member 13. l. have shown the member 11 provided with D internally-projacting fingers 11i Wliich form therebetween the openings 12, which beingA 19B uninelosed at their inner sides, 'are opposite a peripheral surface 15 on the head., rthe spacingis such that the balls mayicontact with this peripheral surfacer'itht escap' v ing from the-openings 12, and in this Way 11o be constantly agitated by the .-rotor. .The surface 15 may be regarded as a peripheral shoulder on the head, andthe cam member as a radially projecting flange in the rear of this shoulder and behind the retaining mem ber 11.

in operation the parts 6, 7 are rotated at high speed, so that the cam member 8 is car ried around behind the balls to force the latter repeatedly toward and against the dia- ,120'

phragm. The latter is preferably entirely lane endirnperforate inside its virtual pe# ripheryfthat is, the inner' circle et its clamped portion, and the balls are caused to deliver perfectly normal thrusts distributed simultaneously'about and distant from its axis. In this way even a large diaphragm may be vibrated in a unitary manner, and without any lateral com onent of thrust, se that the diaphragm is p' aced. under the least 4.5 'Iier and the ring and means on the motor 'possible strain and the similarity or successive sound waves is not impaired. Since the amplitude of' vibration at the regions of thrust is materially less than the complete amplitude of vibration at the center of the diaphragm, balls may be employed with 'ad-- vantage, even though of. small diameter,

- since the extent of thelr reciprocatory move-` ment'is slight. For this reasontheir guide openings 12 may be ot the simplest'iormation, without the necessity of providing them with means for holding'the balls against escape at either end, the` presence of the cam and the diaphragm being suiiicient to insure the retention of the balls.v v

The ca1n8 may be adjusted toward and froin'the diaphragm, either by adjusting the head as has been previously described,l or' by screwing the'. cam forward or'backward on the head or by both, one for coarseland the other for tine adjustment.- The retain-V ing member ll may be adjusted between the cam and the diaphragm, by screwing it forward or backward on the support 13. The4 pitch ot .the'screw threads may be low', so

.that very tine adjustments may be secured.

As previously stated I make no claim herein for the specific means for vibrating `.they diaphragm upon the rotation of the armature shaft'as anyother means might be employed in the combination claimed in place' 'of that shown, and that shown is f claimedin a cti-pending application.

'W hat I do claim and desire to secure, by Letters-Patent is 1. ln a horn, an electric motor having :in

inclosing cup-shaped shell threaded externally atone end. a removable cap across the open` end of the shell and provided with a bearing for theA motor shaft, an internally threaded ring screwed upon the threaded end of the shell, an amplifier secured to the ring, a diaphragm in a plane substantially at right angles to the'motor shaft having its marginal edges; secured between theV ampli-y 5 for-lockingthe shell in' its adjusted ositiom a cap across the open end of the hell and provided with a bearing for the motor shaft, a diaphragm secured to the ring and extending across the adjacent end of the shaft, and means on the motor shaft for vibrating 4the diaphragm.

3. In a horn, a rotary electric motor driv ing a suitable shaft and having an inclosing shell, carrying field coils,l and .bearings for' the motor shaft, a supporting member, lav diaphragm carried thereby andvlocated' sub- 'Vphragin stantially at right angles to said motor shaft, and means carried by said motor shaft for eiiecting' vibrationqo said diaphragm, said shell and said diaphragm-supporting member being. relatively rotatable tojadjust said last mentioned means 4in respect lto the dia- 4. In ahorn, aj rotary electric motor having an inclosing shell provided with an open end, and carrying the field coils, aremov'- able member extending across one end and l.provided with a bearing forv the motor shaft, a Adiaphragm f in la-I plane substantially at right angles to'said-motor shaft, an annular diaphragm supporting member adjustable lengthwise oi and 'upon said shell and means carried by said motorshaft for effecting vibration'ot' said diaphragm, said means being adjustable toward and from said diaphragm upon the relative rotation yof said motor hell' andl said diaphragm supporting memer. f

5. Ina horn, a diaphragm, an annular internally threaded member supporting the same, an electric motor provided with an inclosing cylindrical shell having an axis at -an angle to said diaphragm having exterior threaded engagement with the threaded portion of said member, and a rotor driven by said motor and adjustable toward and from said diaphragm upon the rotation of said motor shell in respect to said member.

6. A hornor signaling device having a diaphragm,- a diaphragm supporting member and a rotary electric motor supported by said member with its shaft'vsubstantially normal to said diaphragm,r and a rotor driven by the shaft of said motor, said motor and .said diaphragm supporting member having threaded' engagement whereby the rotation of one with respect to the other adjusts said rotor toward and from said diaphragm.

- C. A horn or signaling device having a casing member presenting a threaded portion, a dia hragm clamped to said casing member a jacent the periphery of the latter and an electric motor including an armathrefand a casing having a cylindrical threaded Wall and transverse wall, said mature shat, a rotor on said armature shaft between said transverse wall and said diaphragm for vibrating the latter, the thread-4 ed engagement of said shell and' said casing serving to adjust the position of said rotor in respect to said diaphragm.

8r A horn or signaling device having a diaphragm, an annular member supporting the same, a rotary electric motor arranged with its shaft substantially normal to said diaphragm and provided with a casing, a rotor mounted on the motor shaft in operative relation to said diaphragm, and means ad justabl'y connecting said eaing with the Signed at New York citv in the couwye peripheral portion of the diphragm sup- New York and State of blew York thiS Sib porting member, whereby relative adjustday of February A. D. 1913. i ment of said diaphragm and rotor toward f GEORGE C. DEAR and from each other is attainable by a rela- Witnesses: tive rotation of said m'otor casing and said CLAIR W. FMRBANKS, diaphragm supporting member. FLORENCE LEVEN. 

